Electron discharge device comprising a resonator



June 25, 1957 1 5 v s ETAL 2,797,355

ELECTRON DISCHARGE DEVICE COMPRISING A RESONATOR Filed Sept. 30. '1952 INVENTQRS GERRIT DE VRIES G ESINUS DIEMER United htates Patent ELECTRUN DISCHARGE DEVICE COMPRISING A RESUNATDR Geri-it de Vries and Gesinus Diemer, Eindhoven, Netherlands, assignors, by mesne assignments, to North American Philips Company, Inc, New York, N. Y., a cor= poration of Delaware Application September 30, 1952, Serial No. 312,363

Claims priority, application Netherlands November 9, 1951 3 Claims. (Cl. 315-4) This invention relates to devices for producing, amplifying or modulating m-illimetric Waves and comprising an electric discharge tube, wherein the resonant system consists of a number of parallel wires of about one half wavelength, the wires being wound adjacent each. other on a frame with a spacing between their center lines which is small relatively to their length and said wires interacting with an electron beam passing along them.

Devices of the aforesaid type have already been proposed and in order that successive wires shall vibrate in phase-opposition they are alternately made longer and shorter than the average length. This has been described in a copending application, Serial No. 261,102, filed December 11, 1951.

According to the invention in a device for millimetric waves comprising an electric discharge tube, wherein the resonant system consists of a number of parallel wires of about one half wavelength wound adjacent each other on a frame with a spacing between their center lines which is :small relatively to their length and interacting with an electron beam passing along them, the interstices between the wires, measured in the direction of the wires, are alternately shorter and longer than the average length of the interstices in a manner such that the ratio between the smaller length and the greater length is at the most 0.9 but not less than 0.7.

The aforesaid expedient is effective to cause the wires to oscillate alternately in phase-opposition, the operation of the tube then being most effective.

In order that the invention may be readily carried into effect, it will now be described in detail with reference to the accompanying drawing, given by way of example, in which:

Figs. 1, 2 and 3 respectively show a device of the invention and two forms of a wound frame with alternating short and long interstices between the wires.

In Figs. 1 and 2, which are respectively an elevational view of the device and a sectional view of the frame alone, the frame is denoted by 1 and the opening therein by 2, the wires being designated 3. At both ends of the wires there is provided a strip 4 of conductive material bent in the form of a block line or rectangular sine curve. The portions of strip 4 engaging the wires are designated 5, the portions standing clear of them being denoted 6 and the intermediate connections being designated 7. Both strips 4 are provided in a manner such that the interstices are either not shortened or shortened at both ends. Means including a cathode 11, focusing and accelerating means 12 and a collector 13 are provided for projecting an electron beam past the resonator to interact therewith. All of these electrodes are in an evacuated envelope 14.

Fig. 3 shows how a strip-on-edge 8 provided with incisions 9 and teeth 10 is made to engage the Wires.

In both cases the wires are 4 mrns. long and the strips, measured in the direction of the wires, are 0.25 mm. thick.

The height of the blocks and incisions respectively should at least approximately correspond to the spacing of the wires, it being not smaller than one half of the shortening by the strip.

What we claim is:

l. A device adapted for extremely-high frequency operation, comprising a resonator including a planar conductive frame and a plurality of substantially parallel taut wires disposed in spaced relation on and secured to said frame and defining spaces therebetween, each of said Wires having a length substantially equal to onehalf of a Wavelength of the operating frequency of the device, the spacing between adjacent wires being small relative to the length thereof and equal to one another, alternate spaces between the wires having the same length in the direction of the wires, adjacent spaces between the wires having different lengths in the direction of the wires within a ratio of smaller to greater lengths of 0.7 to 0.9, and means for projecting an electron beam past said resonator in a direction parallel to said frame and substantially normal to said wires to cause successive wires to oscillate in phase opposition.

2. A device as claimed in claim 1 in which a strip of conductive material is provided at bothends of the wires and in engagement therewith and which strip is bent in the form of a block curve, the length of the blocks being equal to the spacing between two wires and the height being at least approximately equal to the spacing between said wires and not smaller than the width of said strip, whereby the desired ratio of the lengths of the spaces is afforded.

3. A device as claimed in claim 1 in which a strip of conductive material on edge is provided at both ends of the wires and which strip has incisions whose width and spacing correspond to the spacing between the wires and whose depth is at least approximately equal to said spacing and not smaller than the width of said strip, whereby the desired ratio of the lengths of the spaces is afforded.

References Cited in the file of this patent UNITED STATES PATENTS 2,064,469 Haeff Dec. 15, 1936 2,473,399 Spencer June 14, 1949 2,532,545 Everhart Dec. 5, 1950 2,535,317 Pierce Dec. 26, 1950 2,645,738 Coeterier July 14, 1953 2,697,799 Svensson Dec. 21, 1954 

